The present invention is generally concerned with an envelope having a top closure means for affirmatively retaining the contents of the envelope therein. More specifically, the present invention deals with an envelope in which the aforesaid closure top portion can be engaged in a non-adhesive manner and may be disengaged in a simplified manner by the user thereof.
The prior art includes numerous types of envelopes of various designs, all of which have respective design features applicable to specific purposes for which such various envelopes are utilized. It is contemplated that the envelope of the present invention will be specifically utilized in drive-in bank window situations in which money is passed in a "drive-in bank envelope" between the bank window and an automobile. In such a situation it becomes highly desirable that a closure flap be provided on the envelope to retain the contents of such envelope therein. The prior art has provided envelopes for this purpose which have included simple fold-down flaps on the top of the envelope with adhesive means for sealing the flap against the back of the envelope when in the downfolded position.
Additionally, the prior art includes envelopes having downfolding closure flaps which can be secured to the back of the envelope by mechanical locking of the closure flap to the back panel.
However, all of the prior art envelopes specifically utilized for drive-in bank window applications and for other similar uses in general have included various undesirable features. Specifically, those envelopes having closure flaps which are adhesively secured to the back of the envelope usually must first be "licked" by the individual initially utilizing the envelope wherein the receiver of such envelope must exert a certain amount of effort to either rip the envelope open or slit open the top edge in order to gain access to the contents thereof. In those envelopes having mechanical means for attaching closure flaps to the back panels thereof, such mechanical locking attachments involve folding portions of a closure flap into specifically designed mating locking portions on the envelope in a complicated manner with correspondingly complicated disengagement of such flap also being encountered.